Food effect is a well-known phenomenon that can adversely affect the pharmacokinetics of drug distribution in the body. As a result, many drugs have to be taken either in fasted or fed conditions to achieve the optimum effect. Well known examples include carbamazepine tablets (to be taken with meals), captopril tablets (to be taken one hour before meals), or azithromycin tablets (to be taken 2 hours after meal), while some other drugs remain unaffected by food, as amoxicillin for example.
For this reason, FDA recommends to test bioequivalency of drug products either under fasted or fed conditions, depending on the drug. Moreover, in the latter case the meal itself is standardized.
Little formulation work has been conducted to date in order to overcome this food effect disadvantage.
U.S. Pat. No. 5,529,791 describes an extended release formulation of diltiazem pellets coated with either cellulosic or synthetic polymers, and absence of food effect is reported. However, no link is explained between the composition of the product and the absence of food effect.
Benziger et al., J.Pharm.Sci., 85,4, pp.407-410 (1996) compared the bioavailability of oxycodone formulated as an immediate release aqueous solution or as extended release tablets, under fasted or fed conditions and found a significant difference in availability of the solution while no difference could be observed with the extended release tablets. These authors related the absence of food effect to the use of extended release tablets rather than to any specific formulation parameter.
U.S. Pat. No. 5,879,714 a drug and a water insoluble polymer are mixed into a molten carrier, preferably water-soluble. The only example provided in this patent consists in melting PEG 8000 at 120xc2x0 C. and dispersing nifedipine, stearic acid and Eudragit RSPO in it. After cooling, the solidified mixture is ground into granules. Heat sensitivity of many drugs seems is a major concern when considering applying the process thereto. Absence of food effect is not disclosed but it is indicated that hydrophilic matrix systems are said to be more likely to induce food effect than the disclosed formulation.
U.S. Pat. No. 5,580,578 provides controlled release formulation having a coating consisting essentially in methacrylic copolymers, said coating having been oven cured. Examples disclose compositions comprising a core comprising thee active ingredient (e.g. hydromorphone hydrochloride), an intermediate layer comprising hydroxypropylmethylcellulose and the cured overcoat based on Eudragit. After oven curing, drug products tested clinically were found to be exempt of food effect (this was however not justified by formulation parameters). The coating is comprised of sustained release acrylic copolymers of the type Eudragit RS (comprising optionally Eudragit RL).
None of the above documents teaches or suggests the present invention.
The invention relates to a novel sustained release pharmaceutical composition that is free or devoid of food effect and to a method for alleviating the food effect in the drug release.
The invention thus provides a sustained release composition free of food effect comprising:
(a) a core comprising an active ingredient; and
(b) a functional coating comprising, based on the weight of the coating, from 30 to 80% of a gastroresistant polymer and from 10 to 40% of a hydrophilic silicon dioxide.
The instant invention also provides a process for alleviating food effect in a pharmaceutical composition, comprising the step of coating a core comprising an active ingredient with a functional coating comprising, based on the weight of the coating, from 30 to 80% of a gastroresistant polymer and from 10 to 40% of a hydrophilic silicon dioxide.